Method for promoting levels of medicinal ingredients in cannabis

ABSTRACT

A method for promoting levels of medicinal ingredients in cannabis. The method comprises a step to administering an irradiation of a combined light source including red light, green light and blue light in an indoor growing environment of cannabis. A ratio of photon number between a sum of the red and green light to the blue light is regulated in a range from 4.5 to 9.6. While maintaining the light intensity and other growth conditions, the yields and levels of CBD, secondary metabolites in cannabis, can be increased by up to 20.84%.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation in part of PCT patent Application No. PCT/CN2019/106427, filed on Sep. 18, 2019, entitled “Light Regulation Method for Promoting Accumulation of Secondary Metabolites in Cannabis Plants”, which claims priority of U.S. patent application Ser. No. 16/446,602, filed on Jun. 19, 2019, in the USPTO, the entire content of which are hereby incorporated by reference in their entireties.

TECHNICAL FIELD

The subject matter herein relates to a technical filed of medicinal plants, and in particularly relates to a method for promoting accumulation of secondary metabolites in cannabis.

BACKGROUND

Cannabis (Cannabis sativa L.) is an annual erect herb. The main active ingredient in cannabis plants is cannabinoids. Currently, over 70 kinds of natural cannabinoids are found, which are mainly used in some nervous system diseases, such as multiple sclerosis, motor neuropathy, chronic intractable pain, a drug-induced vomiting. Tetrahydrocannabinol (THC) and cannabidiol (CBD) are the main active ingredients. The level of CBD is a key medicinal quality indicator of industrial hemp mosaic. As a non-psychoactive compound, CBD has excellent tolerance and above-average safety, and is widely used in the field of medical research. CBD exerts analgesic and anti-inflammatory effects through dual inhibition of cyclooxygenase and lipoxygenase. It also has potential medical value in the treatment of schizophrenia, Alzheimer's disease and epilepsy. It also has a good intervention effect for drug-induced mental dependence such as morphine, cocaine, alcohol or the like. Tetrahydrocannabinol (THC) is a psychoactive cannabinoid. It is usually administered orally or inhaled. After being absorbed, it circulates through the blood to various organs and tissues, thereby exerting effects including analgesia, anti-inflammatory, immune regulation, anti-cancer, etc. The levels of THC and CBD are one of the important indicators of high-quality medicinal cannabis. Medicinal cannabis with high levels of THC and CBD has higher medicinal value and economic benefits in the cannabinoid extraction and processing industry. Therefore, the cannabis cultivation and regulation technology for obtaining high levels of medicinal ingredients has important application value. Accordingly, the cultivation technology of medicinal cannabis plants with high levels of CBD and THC has become a difficult point that needs to be solved urgently.

Indoor cultivation of cannabis can obtain plant raw materials with stable level and yield of medicinal ingredients in full years without being affected by seasons, because the indoor cultivation of cannabis has stable environmental factors including light, temperature, humidity, nutrition and the like required for growth. Light is one of the most relevant environmental factors influencing plant behavior. It is not only the basic energy source for photosynthesis, but also an important regulator of plant growth and development, which plays a significant role in plants' morphogenesis, reproductive development, and regulation of secondary metabolites. Cannabis is a light-loving and short-day plant, which is sensitive to light. It is an important technical means to improve the secondary metabolites for medicinal components by adjusting the light quality ratio of the light environment in the growth of cannabis. The way to adjust the light quality ratio of the light environment is feasible and simple for implementation. It will become an effective technology for producing medicinal cannabis with high levels of CBD and THC and provide a reliable way to provide high-quality raw materials for producing cannabinoid.

Plants experience different light qualities through photoreceptors such as phytochromes and cryptochromes. Researchers suggest that the light absorbed by plants is concentrated in the visible part of the wavelength range of 380 to 780 nm. Red light and blue light are essential light qualities for plant growth. The red light is mainly used to generate assimilate and accumulate biomass, and the blue light is a necessary condition for chlorophyll synthesis and chloroplast formation. The blue light affects the morphology of plants by controlling the stomata shape. At the same time, the blue light can also promote the accumulation of secondary metabolites in plants. Green light has always been a controversial light quality. Some scholars believe that it will inhibit the growth of plants, cause short plants and reduce the yield of leafy vegetables. However, different plants may have different optimal spectral formula during growth. It is, therefore, an important research goal to explore cultivation methods that promote accumulation of THC and CBD to realize high-efficiency cultivation and production of medicinal cannabis. LED lights have the characteristics of narrow half-height and flexible spectral design, which have been widely studied. It has become an important research goal of high-quality and high-efficiency cultivation and production of medical cannabis to explore the cultivation methods for promoting accumulation of CBD. However, in the LED light spectrum matching method that promotes accumulation of secondary metabolites in plants, it has not yet disclosed how to promote the indoor cultivation and growth of cannabis plants to achieve a better effect of promoting accumulation of secondary metabolites (i.e. CBD level) in cannabis.

SUMMARY

With respect to the background, one object of the present disclosure is to provide a method for promoting accumulation of CBD (Cannabidiol) level in cannabis by regulating a growing environment of the cannabis.

Specifically, the object of the present disclosure is achieved by the following embodiments.

A method for promoting levels of medicinal ingredients in cannabis. The method is achieved by administering an irradiation of a combined light source including red light, green light and blue light in an indoor growing environment of cannabis; wherein a ratio of photon number between a sum of the red and green light to the blue light is regulated in a range from 4.5 to 9.6 to improve accumulation of levels and yields of THC and CBD in the cannabis.

In some embodiments, a ratio of photon number between the blue light and the entire light source is 9.5-18.0%.

In some embodiments, a ratio of photon number between the green light and the entire light source is 18-42%.

In some embodiments, a ratio of photon number between the red light and the entire light source is 40-70%.

In some embodiments, the light source used in the indoor growing environment of cannabis is a LED light source.

In some embodiments, the blue light has a peak wavelength at 450 nm, the green light has a peak wavelength at 526 nm, and the red light has a peak wavelength at 660 nm.

In some embodiments, a ratio of the photon number of the blue light to the photon number of the red light is 1:4.

In some embodiments, the LED light source is realized directly by a LED chip or by using the LED chip to excite a phosphor material.

In some embodiments, an initial light intensity is 80 μmol/m²s, a maximum light intensity is 1000 μmol/m²s, and a photoperiod is 10-16 h/d.

Compared with the prior art, the present disclosure has the following advantages.

The present disclosure provides an indoor environment light regulation method for promoting accumulation of cannabinoid substances in cannabis. The cannabinoid substances mainly include THC and CBD. By regulating a ratio of photon number between the sum of red (600-780 nm) light and green light (500-599 nm) to the blue light (400-499 nm) in a range from 4.5 to 9.6. Additionally, a ratio of the photon number between the blue light (400-499 nm) and the light source (380-780 nm) is in a range of 9.5-18.0%; a ratio of the photon number between the green light (500-599 nm) and the light source (380-780 nm) is in a range of 18-42%; a ratio of the photon number between the red light (600-780 nm) and the light source (380-780 nm) is in a range of 40-70%. Furthermore, the peak wavelength of the blue light lies at 450 nm; the peak wavelength of the green light lies at 526 nm; the peak wavelength of the red light lies at 660 nm. While maintaining the light intensity and other growth conditions, the yields and/or levels CBD, secondary metabolites in cannabis, can be increased by at least to 20.84%.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a spectral distribution diagram from a LED light source which is realized directly by a LED chip according to the present disclosure.

FIG. 2 is a spectral distribution diagram from a LED light source which is realized by using the LED chip to excite a phosphor material according to the present disclosure.

FIG. 3 is a full spectral distribution diagram from a light source which is realized by using the LED chip to excite a phosphor material according to the present disclosure.

FIG. 4 is a spectral distribution diagram from a light source which is realized directly by a LED chip according to the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

The present disclosure will be further described in detail below with reference to the drawings and specific embodiments, in order to better understand the objective, the technical solution and the advantage of the present disclosure. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of the disclosure.

In the early stage of treatment to cannabis seedling, top branches of strong cannabis mother plant are selected as stem cuttings for plant cutting, or cannabis seeds are selected for sowing. The seedling stage is about 2 weeks. The cannabis seedlings with good rooting conditions are transplanted into the substrate or rock wool for the vegetative growth phase (the vegetative growth stage is about 4 weeks). Each rock wool block has 1 plant, and a density for the transplanted cannabis seedlings is 9 plants/m². The plant is topped when the plant is about 20 cm high for triggering the growth of side branches. After the vegetative growth stage is finished, the plant is moved to the flower promotion stage for flower promotion treatment. The planting density of the plant in the flower promotion stage is 4-6 plants/m². A distinguishment to the male and female flowers is required. The male flowers will be removed, and the female plants will be cultivated. The cultivation environment is set to have a day and night temperature at 24-26° C./21-22° C., humidity at 60-70%, CO₂ concentration at 10000 ppm. Throughout the growth process, the LED light source directly realized by the LED chip is an artificial light source. The spectrum distribution diagram directly realized by the LED chip is shown in FIG. 1. The LED light source as shown provides a light environment for the growth of cannabis. An initial light intensity is set to 80-100 μmol/m²s. As the plant height increases, the light intensity may reach 500-1000 μmol/m²s in the late stage, and the photoperiod is 10-16 h/d. After 7-9 weeks of growth at the flowering stage, the accumulation of levels and yields of CBD, the secondary metabolites in inflorescence of cannabis plants, would be promoted.

Embodiment 1

Top branches of strong cannabis mother plant are selected as stem cuttings for plant cutting. After the plant cutting is finished (the plant cutting stage is about 2 weeks), the cannabis seedlings with good rooting conditions are transplanted into the rock wool or the substrate for the vegetative growth phase (the vegetative growth stage is about 4 weeks). Each rock wool block has 1 plant, and a density for the transplanted cannabis seedlings is 9 plants/m². The plant is topped when the plant is about 20 cm high for triggering the growth of side branches. After the vegetative growth stage is finished, the plant is moved to the flower promotion stage for flower promotion treatment. The planting density of the plant in the flower promotion stage is 4 plants/m². A distinguishment to the male and female flowers is required. The male flowers are removed, and the female plants is cultivated as before. The cultivation environment is set to have a day and night temperature at 24-26° C./21-22° C., humidity at 60-70%, CO₂ concentration at 10000 ppm. Throughout the growth process, the LED light source is used to provide a light environment for the growth of the plant. An initial light intensity is set to 100 μmol/m²s. As the plant height increases, the light intensity reaches 550 μmol/m²s in the late stage, and the photoperiod is 12 h/d. Different LED light sources are provided in the following 4 control examples (Cont. Ex. 1-4) and 14 experimental examples (Exptl. Ex. 1-14). When harvesting, the levels of THC and CBD in the cannabis plants are determined, and the dry weight of the inflorescence is collected at the same time to calculate the yields of THC and CBD per plant. The experimental results are shown in Table 1.

TABLE 1 Spectral composition and Peak characteristics X1, X2, X3, Ratio of Ratio of Ratio of 400-499 nm 500-599 nm 600-780 nm photons in photons in photons in Biological indicators 380-780 nm 380-780 nm 380-780 nm (X2 + CBD THF Inflorescence light source light source light source X3)/ level level DW CBD yield THC yield SN (%) (%) (%) X1 (%) (%) g/plant g/plant g/plant Cont. 6 24 70 15.67 9.94 3.42 135.26 13.44 4.63 Ex. 1 Cont. 25 24 51 2.04 9.68 3.39 128.42 12.43 4.35 Ex. 2 Cont. 7 38 55 13.28 10.15 3.45 134.07 13.61 4.63 Ex. 3 Cont. 27 18 55 2.70 9.55 3.34 126.45 12.08 4.22 Ex. 4 Exptl. 13 24 63 6.69 11.34 3.83 148.52 16.84 5.69 Ex. 1 Exptl. 11 24 65 8.09 11.06 3.75 151.34 16.74 5.68 Ex. 2 Exptl. 9.5 24 66.5 9.52 10.78 3.68 149.87 16.16 5.52 Ex 3 Exptl. 15 24 61 5.67 10.94 3.70 147.03 16.09 5.44 Ex 4 Exptl. 17 24 59 4.88 10.82 3.69 146.57 15.86 5.41 Ex 5 Exptl. 14 31 55 6.14 11.54 3.92 146.98 16.96 5.76 Ex 6 Exptl. 16 29 55 5.25 11.35 3.81 144.26 16.37 5.50 Ex 7 Exptl. 13.5 31.5 55 6.40 11.48 3.89 148.59 17.06 5.78 Ex 8 Exptl. 12 22 66 7.33 11.24 3.78 151.06 16.98 5.71 Ex 9 Exptl. 12 20 68 7.33 11.06 3.74 149.02 16.48 5.57 Ex 10 Exptl. 12 18 70 7.33 10.94 3.67 148.69 16.27 5.46 Ex 11 Exptl. 12 34 54 7.33 11.38 3.80 150.49 17.13 5.72 Ex 12 Exptl. 12 38 50 7.33 11.28 3.75 148.64 16.77 5.57 Ex 13 Exptl. 18 42 40 4.56 11.03 3.72 147.53 16.28 5.49 Ex 14

The results suggest that, compared with control examples 1-4, the light source in experimental examples 1-14 can greatly improve the levels of THC and CBD in cannabis plants, and at the same time increasing the yields of THC and CBD. In particularly, when (X2+X3)/X1=6.14, the levels and yields of THC and CBD are improved the most. Compared with control example 4, the levels of CBD and THC can be increased by up to 20.84% and 17.37%, respectively.

Although green light is a controversial light quality in the art, and some scholars even believe that the green light will inhibit the growth of plants, cause plants to be short and reduce the yield of leafy vegetables. However, in the present disclosure, a method of accurately regulating ratio of multi-band spectral is provided. A ratio of photon number between the sum of red (600-780 nm) light and green light (500-599 nm) to the blue light (400-499 nm) is regulated in a range from 4.5 to 9.6. Additionally, a ratio of the photon number between the blue light (400-499 nm) and the light source (380-780 nm) is in a range of 9.5-18.0%; a ratio of the photon number between the green light (500-599 nm) and the light source (380-780 nm) is in a range of 18-42%; a ratio of the photon number between the red light (600-780 nm) and the light source (380-780 nm) is in a range of 40-70%. Furthermore, the peak wavelength of the blue light lies at 450 nm; the peak wavelength of the green light lies at 526 nm; the peak wavelength of the red light lies at 660 nm. While maintaining the light intensity and other growth conditions, the accumulation of yields and/or levels of THC and CBD, cannabinoid substances in cannabis, can be greatly increased.

It should be noted that the aforementioned embodiments are merely preferred embodiments of the present disclosure, and those embodiments are not to be deemed as limiting the scope of the invention. The scope of the disclosure should be limited by the by the scope of the claims. It will be apparent to those skilled in the art that other modifications and changes may be made without departing from the spirit and scope of the disclosure. 

What is claimed is:
 1. A method for promoting levels of medicinal ingredients in cannabis, comprising: administering an irradiation of a combined light source including red light, green light and blue light in an indoor growing environment of cannabis; wherein a ratio of photon number between a sum of the red and green light to the blue light is regulated in a range from 4.5 to 9.6 to improve accumulation of levels and yields of tetrahydrocannabinol (THC) and cannabidiol (CBD) in the cannabis.
 2. The method of claim 1, wherein a ratio of photon number between the blue light and the entire light source is 9.5-18.0%.
 3. The method of claim 1, wherein a ratio of photon number between the green light and the entire light source is 18-42%.
 4. The method of claim 3, wherein a ratio of photon number between the red light and the entire light source is 40-70%.
 5. The method of claim 1, wherein a ratio of photon number between the red light and the entire light source is 40-70%.
 6. The method of claim 2, wherein a ratio of photon number between the green light and the entire light source is 18-42%.
 7. The method of claim 6, wherein a ratio of photon number between the red light and the entire light source is 40-70%.
 8. The method of claim 7, wherein the light source used in the indoor growing environment of cannabis is a LED light source.
 9. The method of claim 8, wherein the blue light has a peak wavelength at 450 nm, the green light has a peak wavelength at 526 nm, and the red light has a peak wavelength at 660 nm.
 10. The method of claim 8, wherein the LED light source is realized directly by a LED chip or by using the LED chip to excite a phosphor material.
 11. The method of claim 1, wherein in the indoor growing environment, an initial light intensity is 80 μmol/m²s, a maximum light intensity is 1000 μmol/m²s, and a photoperiod is 10-16 h/d.
 12. The method of claim 1, wherein the light source used in the indoor growing environment of cannabis is a LED light source.
 13. The method of claim 1, wherein a ratio of the photon number of the blue light to the photon number of the red light is 1:4. 